Vulnerabilities and exploits

Without some knowledge of memory management, pointers and execution stacks, it’s hard to give a rigorous account of how programs get compromised and thus enable malware to do its thing. This isn’t the time or place for such an in-depth look, but we can at least provide an only slightly hand-wavey account of one way a program might be exploited.

Programs work with input, which might come from a user, a website, another program, a piece of hardware (like a keyboard or a sensor) or a file. For a program to work correctly, that input has to be correctly formed. If it’s not, then it won’t fit nicely into the memory allocated to it, and horrible things can